Flight control coordinator



Dec. 14, 1943.- T. BARBER FLIGHT CONTROL COORDENATOR 4 Sheets-Sheet 1Filed Nov. 10, 1941 Dec. 14, 1943. 1". c. BARBER 2,336,711-

FLIGHT CONTROL COORDINATOR Filed Nov 10,1941 4 Shets-Sheet 2 INVENTOR72/500025 C. BHEBEB ATTORNEY- T. C. BARBER FLIGHT CONTROL CQORDINATORDec. 14, 1943.

4 Sheets-Sheet 3 Filed Nov. 10, 1941 TOR INVE 72/500025 CI gmasz/e BY Q5l lllll ll-Illllllllllrl'lllllllll ATTORNEY Dec. 14, 1943. c BARBER2,336,711

FLIGHT CONTROL COORDINATOR Filed Nov. 10, 1941 4 Sheets-Sheet 4 lNVENTOR72/[00035 C. 5/4/ 552,

TTORNEY Patented Dec. 14, 1943 ilN'i'ED STAS E ATENT OFFICE FLIGHTCONTROL COORDINATOR Theodore 0. Barber, Seattle, Wash. ApplicationNovember 10, 1941, Serial No. 418,579

Claims.

This invention relates to means designed to be used as an aid in thetraining of airplane pilots, and it has reference more particularly tothe provision of means whereby student pilots may be taught, while ontheground, the proper coordination of the usual hand and foot controls,which, in the actual flight of an airplane, are operated conjointly tomaintain the airplane in stable flight.

More specifically stated, the present invention resides in the provisionof a training device for the purpose above stated, which for conveniencewill be referred to as a training cab; this cab being designed to restupon the ground, or upon any suitable floor, and which is preferablysimilar in form and appearance to the pilots cockpit or compartment inthe typical training plane, and is equipped with an instrument panel onwhich a bank indicator is mounted, and an artificial means not undercontrol of the student in training, is provided for causing movements ofthe bank indicator to take place, to simulate those of the bankindicator of a plane in flight. Also, there are hand and foot controls,like those in the typical airplane, operable by the student in the samemanner and by the same coordination as would be required in actualflight, to counteract the artificially induced movements of the bankindicator and thus cause the return of the bank indicator to a stable orneutral indication.

Explanatory to the invention, it Will here be stated that, generallyspeaking, the control and stability of an airplane in normal flight ismaintained by the proper manipulation of ailerons, rudder and elevators.These controls are placed under control of the pilot through the mediacyof right and left foot controls or pedals, and a hand lever, referred toas the stick which lever is pivoted for forward and rearward, and alsolateral oscillations; the direction of flight, or the control of flightbeing dependent upon the conjoint action of the rudder, elevators, andailerons, as actuated by the above mentioned controls.

In the usual arrangement and connection of hand and foot controls, thepivoted stick has cable connections with the planes elevators wherebydirect forward and direct rearward cscillating movements of the stickwill cause actuation of the elevators for directing the plane downwardlyand upwardly. The stick also has cable connections with the ailerons ofright and left wings whereby hinging actuation of the ailerons forbanking toward one side or the other, according to the direction andextent of movement of the stick, may be effected.

The two foot pedals have cable connections with the rudder, and theseconnections provide that the pedals may be used selectively to eflectactuation of the rudder for right or left turning. To those familiarwith this art, it is understood that in making a turn to right, or left,under influence of the rudder movement, it is the accepted practise thatthe stick be actuated at the same time to move the ailerons toaccomplish the proper banking of the plane to maintain it stable duringthe turning operations.

As an aid to flight control, airplanes are normally equipped on theinstrument panel at a location conveniently visible to the pilot, with agravity actuated bank indicator which visibly indicates whether or notthe plane is in stable flight.

It is understood, furthermore, that for the proper or satisfactorycontrol of a plane in flight, there must be proper coordination of thecontrols, as operated by hand and foot. In actual flight, the pilotendeavors to maintain the bank indicator at a neutral indication, inturning and banking, as well as in straight flight, and this may beaccomplished through the proper coordination of the hand and footcontrols, the exact manipulations of which might vary under differentflying conditions and at different speeds, and while in some unusualsituations, stability in flight might be maintained by the manipulationof hand or the foot controlled devices individually, it is the usualpractise, and is the accepted procedure, that stability be accomplishedthrough the conjoint and properly coordinated action of foot and handcontrols.

In View of the foregoing, it has been the principal object of thisinvention to provide means for expediting the training of student pilotsin the rudiments of handling and controlling an airplane in flight, andmore particularly for expediting the teaching of proper coordination ofmovements of hand and foot controls, to maintain stable flight.

The invention also has for its object to provide improvements upon thedevice of my copending application, filed on February 11, 1941, underSerial No. 378,407, particularly in the simplification of means forcausing the various movements of the bank indicator which are tosimulate those indicating conditions of unstable flight, and also in themeans and devices operable under control of the hand and foot actuatedmembers, for causing the application of compensating influences, orcounteracting forces on the bank indicator whereby to cause it to returnto its neutral position or to a position indicating the desiredstability of flight.

Still another object of the invention is to simplify the structure ofthe device which is the subject of the above mentioned application,particularly by the elimination of the more or less complicatedarangement of cable connections between the hand and foot controls andthe bank indicator, and to employ in their stead simple and practicalelectrical equipment and controls accomplishing the same results.

Still other objects of the invention reside in the details ofconstruction of parts, in their relationship, and in their mode ofoperation, as will hereinafter be fully described.

In accomplishing these and other objects of the invention, I haveprovided the improved details of construction, the preferred forms ofwhich are illustrated in the accompanying drawings, wherein- Fig. l is aperspective view of the present training cab.

Fig. 2 is an enlarged sectional view of the same, in the longitudinalvertical plane.

Fig. 3 is a horizontal section on line 5-3 in Fig. 2.

Fig. l is an underside View of the cab floor, showing the relationshipof parts mounted thereby.

Fig. 5 is a detail of the motor driven means for efiecting theartificial actuation of the bank indicator.

Fig. 6 is a cross section on line 6 showing the joy stick mounting.

Fig. 7 is a cross section on the line ii in Fig. 3 showing the footpedal mountin Fig. 8 is a view showing the manner of mounting the stickand wheel which may be used as an alternative in lieu of the stick asshown in 3 in Fig.3

Fig. 6.

Fig, 9 is a side View of the parts as seen in Fig. 8.

Fig. 10 is a horizontal section on line ii -i9 in Fig. 8.

Fig. 11 is a wiring diagram and diagrammatic illustration of theelectrical controls.

Fig. 12 is a detail of the mounting of one or" the rheostats used.

Fig. 13 is a plan of the same.

In brief, the present invention comprises a training cab, resembling thecockpit section of an airplane, and equipped with a bank indicator andmeans whereby the bank indicator may be caused to move from side to sidewith rather irregular and varying movements. Also, wherein means isoperable under control or" hand and foot controls, like those of thetypical airplane, whereby to counteract the moving influencesartificially produced on the bani: indicator and which cause itsirregular movement, so that the indicator may be maintained at a neutralposition. It is the intent that the coordinated movements of hand andfoot controls must be substantially the same in this training cab, tomaintain a stable indication of the bank indicator, as would be requiredin an actual flight under like action or indications of the bankindicator.

Referring more in detail to the drawings- The training cab embodied bythis invention preferably is in accordance with the showing of Fig. l,and for most satisfactory results is made to resemble the cockpitportion of a typical air plane. Such cabs may be constructed in variousdimensions and of difierent materials suitable for its intended purpose.As here shown, the cab has a horizontal floor i, right and left sidewalls 2 2', front and rear end walls 3 and 3, and a cowl Theconstruction of the cab resembles that found in an open cockpit airplaneand there is a chair, or seat 5 for occuancy by a person in training,and forwardly of the chair, and directly below the cowl, is aninstrument panel 6.

For convenience in use of the cab, the side wall 3 thereof is equippedwith a hinged door "i giving easy access to the cockpit. It is also tobe observed that the horizontal floor E is supported somewhat above thelevel of the foundation on which the cab rests in order to give thenecessary clearance for parts supported below the door, as willpresently be explained.

Disposed transversely of the cockpit, in its forward portion and closelyadjacent the floor, is a horizontal tube or shaft it, rigidly supportedby brackets ii that are welded thereto near its ends and which arebolted or otherwise secured to the floor l. Revolubly supported by thetube, or shaft 58, at its opposite ends and adapted for independentoscillation, are upwardly directed, right and left foot pedals l2 andI'd, each of which has a lever arm projecting doumwardly therefrom,extending somewhat below the floor through openings therein. Theopenings in this showing are designated by reference numerals i5, andthe downwardly extendins levers, for foot pedals i2 and i3, aredesignated respectively by numerals i211 and i360.

By reference to Fig. 8, which shows the parts at the underside of thefiOOl I, it will be observed that a coiled spring it is associated witheach of the levers i205 and idea, and are attached unde' tension to thelower ends of these levers. Also, the springs have connection with posts5? fixed in and extended downwardly from the floor. Also, there is acable l3 attached at its opposite ends, respectively, to the lower endportions of the lovers 52a and lEa, and extending forvardly therefromand about laterally spaced guide sheaves id and 26, providing that apart of the cable extend transversely of the floor. The pull of the twosprings E6 on the levers causes the cable it to be drawn taut andprovides further that forward pressure on either one of the pedals willeffect a corresponding rearward movement of the other pedal; this beinga condition like that in training airplanes.

Referring now more particularly to Figs. 2 and 3, it is to be observedthat bearings 22 and 23 are fixed in spaced relationship on floor I inthe central, longitudinal line of the cockpit, rearwardly of the crossrod l5 and forwardly of the seat 5, each hearing member having anattaching cracket 2d.

Rotatably supported by the hearings and 23 are the forward and rearwardends of a horizontal shaft comprising a tubular outer portion 26 and around rod 2'5 that has a part thereof telescopically and rigidlycontained in the tube. Th forward end portion of the tube 26 isrevolubly threaded into the forward bearing while the rearward end ofthe rod 2?, which extends somewhat beyond the rear end of the tube, isrevolubly threaded into the bearing 21. A lateral ear 23 is fixed on therear end of tube 26, and coinciding with this and fixed on the rod 2'!is a lateral ear 29, a bolt 5% is threaded through the ears 23 and 28 tothe tube and rod against relative rotation. This particular connectionwill later b referred to in describing the use of the alternative stickshown in Figs. 6 and 7.

A lever arm 32 is fixed rigidly to and extends directly downward fromthe forward end portion of the tube 25, passing through an opening 33 inthe floor. Located below the floor, at opposite sides of the opening,and transversely directed, are coiled springs S t-J4 which have innerends fixed to the lower end portion of the lever arm 32 and their outerends fixed to posts or studs 35 in the floor. These springs extendlaterally in opposite directions from the lever arm and are fixed underbalanced tension whereby the lever arm is normally yieldingly held invertical position.

Fixed to the rearward end portion of the rod 27 and extending equally toopposite sides thereof is a tubular cross rod 80, and pivotally mountedby the cross rod is the mounting means for the joystick. This, as bestshown in Fig. 6, comprises a yoke having opposite side straps ll and H,spaced at the medial portions, then directed toward each other andjoined together along their lower end portions, and with their upper endportions directed toward each other and fixed to the opposite sides of asocket member 44 in which the lower end of a lever, or stick i isfitted. The two side straps 4i and 4 i of the yoke pass across theopposite ends of the tubular cross member 4!], and a pivot bolt 46 isextended therethrough and through the tube to thereby pivotally mountthe yoke for forward and rearward oscillation of the stick, and it willbe understood also that the stick may be oscillated laterally inopposite directions by reason of the rotatable mounting of thelongitudinal support in the bearings 22 and 23.

The lower end portion of the yoke that is formed by the uniting of thelower end portions of the straps-4I ii', extends down through an openiw38 in the floor 1. At the under side of the fioor, coiled springs E9 and'50 extend forwardly and rearwardly from the opening 48. These springshave adjacent ends fixed to the lower end portion of the yoke, and havetheir other ends fixed, respectively to posts 5! and 52 that are fixedin the floor. These two springs are under balanced tension and normallyact to retain the stick in an upright, neutral position.

One of the features of this invention resides in the provision for aninterchangeable use of two diiferent types of hand controls; one beingthe usual joy stick already described, which may be oscillated from aneutral upright position, laterally from side to side, and also fromfront to rear,

while the other type of control comprises a lever,

or stick, that may be moved directly forwardly or rearwardly for controlof the elevators but in lieu of the lateral movements for control of theailerons, carries at its upper end a rotatable hand wheel with cableconnections for the rotative action of the tube 26.

To use this alternative type of stick, it is required that the bolt 36which fixed the parts 26 and 21 against relative rotation, be removed,the joy stick 45 withdrawn from its socket, the alternative stickapplied to the socket, and parts attached to the floor as will now bedescribed.

The alternative device has been illustrated in Figs. 8 to where the joystick 45, as previously used, has been replaced by a stick 53 whichlikewise is removably applied to the socket 64L This stick is providedwith laterally extending and downwardly inclined brace rods 55 and 55'which, at their lower ends, have pivoted connection with brackets 56 and56' that are fixed to the floor at opposite sides of the floor opening48. The pivotal connections are affixed by means of bolts 51 whichextend through the lower ends of the brace rods and the correspondingbrackets, and it is to be observed that the bolts 57 are alinedcoaxially with the horizontal pivot bolt 46.

Rotatably mounted at the upper end of the lever 53, is a hand wheel 6!]fixed on a supporting shaft 6! that revolves in a bearing 62 at theupper end of the stick. Fixed on the shaft is a pulley 63 about which acable 64 is wound and secured, with the opposite end portions of thecable extended downwardly and laterally and attached, respectively, tothe ends of laterally and rearwardly extended lever arms 65 and 65'fixed to the tubular member 26. These arms also extend to the axial lineof the bolt 46 where the cable connections are made therewith.

In the use of this alternative control, with the bolt 3!! removed fromthe ears 28 and 29, the tubular member 26 may be rotated by the turningof the hand wheel through the mediacy of the cable connections. Thestick 53, however, still has a forward and rearward movement like thatof the joy stick 45 previously described.

For the purpose of training the student pilot in control coordination,there is provided centrally, or at other location conveniently visibleupon the instrument panel 6, a bank indicator 70. This indicator, inthis instance, is an electrical instrument and is mechanicallycontrolled to artificially produce certain movements of its indicatorelement which are intended to simulate those of a bank indicator in anairplane when fiying in an unstable manner. Also, there are meanscontrolled by the student pilot for counteracting and compensating forthese artificially produced movements of the bank indicator; it beingthe intent that the pilot in training shall, by those certaincoordinated movements of the hand and foot controls, as would berequired in actual flight, cause the application of counter-actingforces which will maintain the bank indicator at, or return it to astable indication.

The bank indicator 70 in this instance, is an instrument like anordinary milliammeter operating as a galvanometer. This indicatorcomprises a housing 14 that is fixed to the panel 6. In the housing isthe usual resistance coil, not shown, with terminal connections 76 andH. Also, there is the bank indicator needle 18, normally verticallydisposed at its zero or neutral position, and movable in oppositedirections therefrom. The positive and negative poles l6 and Ti of theindicator are electrically connected, respectively, by circuit wire 82and 83 as illustrated in Fig. 11, with the movable resistance varyingelements of rheostats 8i! and 8!, as seen in Fig. 11.

A source of electrical current here provided by use of a storage batteryindicated at 84, has circuit wires 85 and 86 leading from its positiveand negative terminals to poles 81 and 88 of the rheostat Bi, and asnoted in Fig. 11, the rheostat 89 has its poles 89-90 electricallyjoined by wires 9! and 92 with the wires 85 and 36.

The two rheostats, 8B and 85, are associated with the mechanicalequipment in the manner best illustrated in Fig. 4, wherein it is shownthat the rheostat 8! is mounted on the under side of the floor I nearthe transverse run of cable l8. Each rheostat comprises a housing inwhich there is a resistance coil and a contact movable therealo-ng bythe movement of a lever arm extended from the housing. The resistanceelement of the rheostat BI is designated diagrammatically in Fig. 11 bynumeral Ma and a movable resistance varying contact is designated at B5and is fixed on a pivot shaft 95 which has an actuating lever arm El.This arm Ell has a cable connection 98 with the cable it, and a coiledspring 93 is attached under tension to the lever to keep the cable 9 3taut. Thus, since the cable i3 will be moved in opposite directions inaccordance with depression of the foot pedals i2 and it, it can be seenthat the lever 97 will be caused to move accordingly by reason of itsconnection with cable l8. This will actuate the contact member 5 5 alongthe resistance coil 8 i a.

The rheostat 8d, likewise, has a housing Silas, a resistance element55a, and a resistance varying contact member lei on a pivot shaft N32 towhich an actuating lever arm H313 is fixed. The arm I83 has a cableconnection iil i with the lower end of the joy stick yoke and a coiledspring 665 is attached under tension to arm iilt to keep the cable taut.

In the use of the rheostat 83, its housing Eda: is rotatably mounted bya pivot tube Hi8 carried by a bracket Hi3 fixed to the under side offloor I. Fastened to the housing 8dr is a lever arm 1 l2, and the outerend or" this arm has a link 5 i3 pivotally connecting it with one arm, Mld of a bell crank lever lid, operable as presently described, torotatably move the housing, thus to cause relative movements of theresistance element 86a and contact member lei.

It will now be understood, by referring to Fig. 11, that with bothrheostats in neutral setting, the indicator needle ii of the bankindicator it will be located at a neutral indication. However,

should the contact element of rheostat 55 be moved toward either side bya relative movement of the resistance and contact element, this willcause movement of the bank indicator to one side or the other and theextent of movement and direction will be in accordance with the extentand direction of rotative movement of the housing. Thus, it is possibleby this means to produce movements of the bank indicator to simulatethose of the bank indicator of an airplane in unstable flight. Theseartificially produced movements can be made H1016 or less erraticthrough actuation of the bell crank lid, and in this instance, I haveshown it to be actuated by the rotation of a plural-lobed cam 529 thatis fixed on a shaft 52! driven by an electric motor i222 throughsuitable gear reduction, as at i 53, that may be fixed in any suitablemanner to the under side of floor 5 or at any other suitable place.

Assuming the rheostats and bank indicator to be so arranged, andelectrically connected, their use for training a student pilot incoordination of controls is as follows:

First, the electric motor M22 is energized and set in operation so thatthrough the action of cam E23 and bell crank mechanism disclosed, thehousing 85$ of the rheostat 88 will be given rotative movements ofvarious amounts in opposite directions. These rotative movements ofhousing 8% cause a relative adjustment of the contact element along theresistance coil of the rheostat, and in accordance with the Well knownprinciples, thus cause the needle of the bank indicator to move fromneutral indication toward one side or the other to varying extent inaccordance with the action of the housing under influence of the camlZii.

Since the purpose of the present apparatus is to teach coordination ofhand and foot controls, and since the student is taught as a fundamentalprinciple that by proper coordination of their movements, the bankindicator can be brought back to show a neutral indication, it will beunderstood therefore that should the bank indicator needle swing to theleft, indicating a high right wing, the proper correcting action of thejoy stick is to press it to the right. This causes a compensatingmovement of the rheostat lever arm IE3, tending thereby to counteractthe movement of the resistance element which has been caused by the bellcrank linkage. At the same time, the student depresses the correspondingfoot pedal, thereby moving the cable l8 so that through the lever 9? andspring connection, the contact element of the rheostat ti is movedaccordingly; it being understood that is the contact element of therheostat 55 is caused to move one direction, the contact element of theother rheostat should be moved correspondingly the opposite direction,thus to effect a balance of resistances which will stabilize the needleof the indicator 18.

With the bank indicator thus being artificially moved from side to sideto varying degrees, the student pilot may be taught the propercoordinated movements of the hand and foot controls and how to effectthe bringing of the needle back to a neutral indication, and since thesecoordinated movements are the same in this training device as arerequired in the actual flying plane, the training period for thisparticular type of instruction can be materially shortened and alldanger removed.

In order that the intensity of the movement of the needle 78 of theindicator may be somewhat controlled, I provide a variable resistance asat I25 interposed in the wire 85. This may be controlled by a button asat I25 located on the instrument panel. Also, there maybe a suitableswitch as at lei? for opening or closing the circuit.

The subject matter contained in this case covers a stationary or groundtrainer for teaching coordination of hand and foot controls as used inan airplane in flight for maintaining stability in flight, and theinvention features the use of a ball bank simulator element and anartificial means for causing typical flight movements thereof, incombination with means operable under control of the hand and footcontrols, Whereby the moving influence of the artificial means may benullified, thus to cause the ball bank simulator element to assume aposition that would indicate stable flight. In use of the term typicalflight movements, I mean movements from right to left of the bankindicator, such as are produced when an airplane is in unstable flight;it being understood that the ball bank indicator is in neutral positionwhen the plane is stabilized.

Having thus described my invention, what I claim as new therein anddesire to secure by Letters Patent is:

1. In a coordinator of the character described, in combination, anelectrically energized bank indicator simulator having a movableindicator element, means for causing the application of variableelectric iorces to said indicator to effect typical movements of theindicator element of varying degree and direction, movable right andleft foot controls adapted to be selectively actuated by the users feet,a hand control adapted to be actuated to right or left by the usershands, and means operable under the conjoint control of the said handand foot controls for producing counteracting electrical influences inthe bank indicator simulator, variable in direction and extent inaccordance with the selection or controls and extent of their movement,and whereby the indicator moving forces may be nullified.

2. A coordinator of the character described comprising in combination,an electrically energized bank indicator simulator having an indicatorelement movable from a neutral indication to right or left according todirection of flow of current and potential on its terminals, selectivelyoperable right and left foot controls, a hand control lever selectivelymovable from neutral position to right and left sides, an electricalresistance element associated with the hand control, a source ofelectrical energy with connections from its positive and negative polesto the opposite ends of each of the resistance elements, a contactor foreach resistance element, means electrically connecting the contactorsrespectively with the terminals of the bank indicator, means for causingrelative movement of one of the contactors along its resistance, andmeans operable by movements of said hand and foot controls to right orleft to adjust the contactors along the resistance elementscorresponding thereto accordingly to eiTect the neutralization of forcesin the indicator.

3. A coordinator of the character described comprising, in combination,right and left foot pedals operable selectively by the users feet, ahand control member operable selectively to right or left by the usershands, an electrical resist ance element associated with the footcontrol pedals having a contactor movable therealong, a resistanceelement associated with the hand con trol, and a contactor movabletherealong, a bank indicator simulator comprising a galvanometer havingits opposite poles electrically connected respectively to the contactorsof said resistance elements, a source of electrical energy havingelectrical connections from its positive and negative poles,respectively, to the opposite ends of the said resistance elements,mechanically driven means for causing movement of one of the contactorelements in different direction and extent along its resistance coil tochange potential on the galvanometer terminals and effect typicalmovements of the galvanometer needle, and means movable with the footpedals and other means movable by the hand control to cause areadjustment of the contact elements along their correspondingresistances to efiect the neutralization of the needle moving influencein the gal- Vanometer.

4. In a coordinator of the character described, a set of foot pedalsadapted to be depressed respectively by the users right and left feet, ajoy stick operable to right and left from neutral by the users hands,springs acting on the pedals and on the stick to yieldingly retain themat their neutral positions, a cable connection between the pedals andmovable in opposite directions according to the depression of one or theother of the foot pedals, an electrical resistance coil associated withthe pedals, a contactor for the coil, and means connecting the contactorand cable whereby the contactor will be moved in opposite directionsalong the resistance according to the pedal depressed, a resistance coilassociated with the joy stick, a contactor for the coil, and meansconnecting the contactor and joy stick for moving the contactor alongthe coil in opposite directions and extent as determined by thedirection and extent of movement of the stick, a source of electricalenergy having positive and negative poles electrically joined with theopposite ends of said resistance coils, and a bank indicator simulatorcomprising a galvanometer having its opposite poles electricallyconnected with the said contactors, and mechanically operable means foreffecting the movement of one of the resistance coils and its contactorsto produce action of the bank indicator needle.

5. A stationary coordinator trainer for airplane fiight trainingcomprising a cockpit frame, hand and foot control devices, and a turnand bank indicator element simulating parts of an airplane; an auxiliarymeans operable to cause typical flight movements of the turn and bankindicator element, and means associated with the said auxiliary meansand operable by the hand and foot control devices to counteract themovement producing action on the indicator element of the said auxiliarymeans.

THEODORE C. BARBER.

